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Area by DMD, traverse ABCDEA (-5.693)

Short answer

Using the Double Meridian Distance method with the given latitudes and departures, area = 2028.41 m² (0.2028 ha).

Calculate the area of the following traverse ABCDEA by double meridian distance method.

LineABBCCDDEEA
Latitude (m)-5.693-21.361-28.201+1.103+54.242
Departure (m)-33.990-13.911+18.867+28.608+0.426

The latitudes sum to 0.090 m and the departures to 0.000 m. The latitude misclosure of 0.090 m is small (about 1 in 2,000 of the perimeter of about 177 m), so the given figures are used without adjustment.

DMD method

DMD rule (taking the meridian through the starting station):

  • DMD of the first line = departure of the first line.

  • DMD of any line = DMD of the previous line + departure of the previous line + departure of the line itself.

  • DMD of the last line = departure of the last line with opposite sign (a check).

  • Double area = Σ (latitude × DMD), and area = ½ |Σ L × DMD|.

  • DMD(AB) = D(AB) = -33.990

  • DMD(BC) = -33.990 + (-33.990) + (-13.911) = -81.891

  • DMD(CD) = -81.891 + (-13.911) + (18.867) = -76.935

  • DMD(DE) = -76.935 + (18.867) + (28.608) = -29.460

  • DMD(EA) = -29.460 + (28.608) + (0.426) = -0.426

  • Check: DMD(EA) = -0.426 = −D(EA) = -0.426, so the DMDs are correct.

LineLatitude L (m)Departure D (m)DMD (m)L × DMD (m²)
AB-5.693-33.990-33.990193.505
BC-21.361-13.911-81.8911749.274
CD-28.20118.867-76.9352169.644
DE1.10328.608-29.460-32.494
EA54.2420.426-0.426-23.107
Sum0.0900.0004056.821
Area=∣4056.821∣2=2028.411 m2\text{Area} = \frac{|4056.821|}{2} = 2028.411\ \text{m}^2

Answer: Area = 2028.41 m² (0.2028 ha).

(If the latitudes are first balanced by Bowditch's rule, the area changes only slightly, to about 2030 m².)

✓ Answer checked by Claude Opus 5.5 (high effort)

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